Problem Solving Qualitative Physics SPM Paper 2

Perfect Score Module2009 / Physics/ Problem solving (Qualitative)

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Question 1 A transformer is connected to a 240 V of a.c power supply. Modification has to be made to transformer so that the transformer can be used as an efficient 6 V mobile phone charger. . Suggest the modification to be made to the transformer, based on the aspect below:

(i) can produce 6 V of output voltage (ii) can produce steady direct current (iii) has high efficiency

[10 marks] Question 2

Based on Diagram 2, .

(i) Explain one modification to the large piston that enables the jack to lift a heavier load,

[2 marks]

Diagram 1

Diagram 2


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Question 3 Diagram 3 shows a transistor is used to light up during the day. (i) Suggest a modification to light up the lamp at night. [4 marks] (ii) A student replaced lamp L with a lamp labeled 240 V, 24 W in Diagram 4.3. The bulb is not light up.

(a) Why the lamp is not light up? (b) An electrical component is connected to the output transistor so that the lamp

is light up. Name the electrical component and state the functions. [2 marks] Question 4 Diagram 4 shows an electric circuit that has a transistor that acts as an automatic switch. (a) Explain the modification(s) that need to be done towards the circuit so that it can be used as an automatic switch that will ring the alarm when a fire breaks out. [4 marks] Question 5

Diagram 3

Diagram 4


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Figure 5.1 and 5.2 illustrate the working principle of a hydrometer. The depth to which the test tube sinks depends on its surrounding liquid.

Explain how would you design a hydrometer that can determine a wide range of densities of liquid, using the idea of the working principle of a hydrometer shown above. Draw a diagram that shows the design of your hydrometer and in your explanation, emphasis the following aspects:

(i) the stability of the hydrometer (ii) the sensitivity of the hydrometer (iii) the ability to measure a wide range of densities of liquids (iv) the calibration of the hydrometer

[10 marks] Question 6 Figure 6 shows the seashore of a fishing village. During the rainy season, waves are big. One year the waves eroded the seashore, caused the jetty to collapse and damage the fishermen’s boats. To prevent similar damage in the future, the fishermen suggest building retaining walls and relocating the jetty. Make further suggestions of ways to help the fishermen solve their problems You should use your knowledge of reflection, refraction and diffraction of waves to explain these suggestions, to include the following aspects:

(i) the design and structure of the retaining wall (ii) the location of the new jetty (iii) the size or energy of the waves

[10 marks]

Diagram 5.1 Diagram 5.2

Diagram 6


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Question 7 Diagram 7 shows an electric motor which is supplied with a 12 V a.c

(i) Explain how the motor is able to rotate. (ii) Using a 12 V a.c power supply, explain the modification that needs to be

done on the motor and the external circuit to enable the motor to be a d.c electric motor and rotate faster.

[10 marks] Question 8 Diagram 8 shows a sailboat. You are required to give some suggestions to design a sailboat which can travel faster. Using the knowledge on motion, forces and the properties of materials, explain the suggestions based on the following aspects:

(i) the surface of the board (ii) the shape of the board (iii) material used for the sail (iv) the size of the sail

[10 marks]

Diagram 8

Diagram 7


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Question 9 Diagram 9 shows the structure of an optical fibre used in telecommunications. Optical fibre are made of fine strands of glass. Each single fibre (inner core) is coated with a thin layer of another type of glass (outer cladding). You are required to give some suggestions in designing an optical fibre which can carry more information. Explain your suggestions base on the following aspects:

(i) refractive index of inner and outer glass (ii) flexibility (iii) thickness (iv) strength (v) density of the glass

[10 marks] Question 10 [forces and motion] Diagram 10 shows a student trying to launch a water rocket. You are required to give suggestion on how to design a water rocket for National Competition. Based on your knowledge on forces, motion and properties of materials, explain your suggestion based on the following aspect:

(i) material used (ii) shape of the rocket (iii) suitable angle to launch the rocket (iv) volume of water in the rocket (v) added structure for the motion of the rocket

[10 marks]

Diagram 9

Diagram 10


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Question 11 A chef has to cook for a banquet and he has to be able to prepare his food quickly, with the minimum cost yet without compromising on the quality of the food served. Using the appropriate physics concepts, suggest and explain suitable designs or way to have a pot with the following features:

(i) long lasting and safe to be used (ii) portable (iii) consume little fuel (iv) versatile (adaptable for various purpose : cooking, steaming etc )

[10 marks]

Question 12 Using the knowledge on reflection of light, explain your choice of anti-theft that is used to have a clear view the interior of the shop, based on the following aspect:

(i) the type of mirror (ii) the diameter of the mirror (iii) the curvature of the mirror (iv) the thickness of the mirror (v) The position of the mirror

[10 marks] Question 13 As an engineer you are agree given the task of determine the type of wire that is suitable to be used for connecting electric devices in a house. Explain the suitability of the following aspect:

(i) resistance of wire (ii) melting point of wire (iii) density of wire (iv) rate of rusting (v) rate of expansion of wire

[10 marks] Question 14 You are given two convex lenses, P and Q with focal lengths 40 cm and 5 cm respectively. Both the lenses are used to build a simple astronomical telescope at normal adjustment.

(i) Using the two lenses, explain how you are going to build the simple astronomical telescope.

(ii) Suggest modifications that need to be done on the telescopes to produce clearer and bigger images. [10 marks]


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Question 15 The assembly hall of SRK Taman Hijau is small in size and produces too much echo. The administrator intends to replace the old building with new one. The new hall should be able to accommodate at least 800 students and is suitable for holding other activities like concerts. Suggest the modification should be made to the old hall. Based on your knowledge on wave characteristics, explain the modifications based on the following aspects:

(i) the design of the hall (ii) the furnishing of the hall (iii) the sound and lighting system of the hall

[10 marks] Question 16 When transferring and receiving electrical energy, poles such as those shown in Diagram 11 play an important role. By using your knowledge on the transfer of electrical energy and Diagram 11, explain

(i) the safety features that are needed to build the poles (ii) the properties of the cables that are used

[10 marks]

Diagram 11

Problem Solving Qualitative Physics SPM Paper 2

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